It has previously been proposed to include return mailer envelopes in brochures, see R. E. Katz U.S. Pat. No. 4,084,696 granted Apr. 18, 1978. However, the '696 envelope sheet has certain drawbacks. For example, it has an envelope portion which is double thickness, while the remainder of the sheet is a single thickness of paper. For stacking and printing on sheets of paper, it is important that the paper be of uniform thickness to provide regular stacking and to avoid jamming of the copier. In addition, the '696 patent has exposed adhesive which could be activated under high humidity or damp conditions. With exposed activated adhesive, sheets may stick together and laser or ink jet printers may jam or become contaminated.